diff --git a/toolkit/components/url-classifier/src/nsUrlClassifierHashCompleter.cpp b/toolkit/components/url-classifier/src/nsUrlClassifierHashCompleter.cpp
index b838fe07b99..67636277b0b 100644
--- a/toolkit/components/url-classifier/src/nsUrlClassifierHashCompleter.cpp
+++ b/toolkit/components/url-classifier/src/nsUrlClassifierHashCompleter.cpp
@@ -125,7 +125,10 @@ nsUrlClassifierHashCompleterRequest::OpenChannel()
   LOG(("nsUrlClassifierHashCompleterRequest::OpenChannel [%p]", this));
   nsresult rv;
 
-  rv = NS_NewChannel(getter_AddRefs(mChannel), mURI);
+  PRUint32 loadFlags = nsIChannel::INHIBIT_CACHING |
+                       nsIChannel::LOAD_BYPASS_CACHE;
+  rv = NS_NewChannel(getter_AddRefs(mChannel), mURI, nsnull, nsnull, nsnull,
+                     loadFlags);
   NS_ENSURE_SUCCESS(rv, rv);
 
   nsCAutoString requestBody;
diff --git a/toolkit/components/url-classifier/src/nsUrlClassifierStreamUpdater.cpp b/toolkit/components/url-classifier/src/nsUrlClassifierStreamUpdater.cpp
index 2610b1cbfa5..16a99ab36c3 100644
--- a/toolkit/components/url-classifier/src/nsUrlClassifierStreamUpdater.cpp
+++ b/toolkit/components/url-classifier/src/nsUrlClassifierStreamUpdater.cpp
@@ -134,7 +134,10 @@ nsUrlClassifierStreamUpdater::FetchUpdate(nsIURI *aUpdateUrl,
                                           const nsACString & aServerMAC)
 {
   nsresult rv;
-  rv = NS_NewChannel(getter_AddRefs(mChannel), aUpdateUrl, nsnull, nsnull, this);
+  PRUint32 loadFlags = nsIChannel::INHIBIT_CACHING |
+                       nsIChannel::LOAD_BYPASS_CACHE;
+  rv = NS_NewChannel(getter_AddRefs(mChannel), aUpdateUrl, nsnull, nsnull, this,
+                     loadFlags);
   NS_ENSURE_SUCCESS(rv, rv);
 
   mBeganStream = PR_FALSE;